Three-dimensional surfaces are often represented in computer memory by a contiguous collection of tiles, such as triangular tiles. Such a representation may be referred to as a “tesselation” or a “mesh.”
A “local activation time” (LAT) of a particular area of the heart is the time at which the wavefront of electrical propagation passes through the area. A local activation time is typically measured from a particular reference time, such as a particular point in time in the QRS complex of a body-surface electrocardiogram (ECG) recording.